Recently I was facing an issue in our project implementation and certain business users were unable to activate Real time workflow. When I checked security role found out that the privilege was given properly:

What went unnoticed is for Real-time workflows a new privilege has been introduced by Microsoft which is shown just below this privilege:

Once this was resolved, automatically business users were able to activate real-time workflows.

Hope it helps!

In CRM 2013 SP1 and all online versions,Or condition is available in workflows now:

Complex conditions with and and or can also be formed easily now:

Hope it helps!